Third Party IP Phone Support on CUCM

--> CUCM supports two categories of RFC 3261-compliant third-party SIP phones.

--> Two different types of third-party SIP phones can be added to CUCM.

--> Third-party SIP phones may be added as basic or advanced phones.

--> Basic Third-Party SIP Phones support only one line and consume three device license units.

--> Advanced Third-Party SIP phones support up to eight lines maximum and supports both voice and video.

--> Advanced Third-Party SIP phones consume six device license units.

--> Third Party SIP phones cannot be registered to CUCM with the help of MAC Address.

--> Third Party SIP phones are registered to CUCM by using SIP Digest Authentication.

--> SIP Digest Authentication configuration need to be done on CUCM as well as Third Party SIP phone.

--> Digest Authentication is based on client/server model.

--> Both CUCM and the third-party SIP phone have to be configured with a username and password for digest authentication in order to work properly.

--> Third-party SIP phones support only a few features compared to Cisco IP Phones using SCCP or SIP. The features that are not supported include but are not limited to the following:

- MAC address registration

- Phone buttons template

- Soft key templates

- Cisco IP phone services

- Cisco Unified Communication Manager Assistant

- Cisco Unified Video Advantage

- Call Pickup

- Presence

- Barge